Plastida is a specific organela found in plant cells. In plastida there is a pigment substance. The mechanism of action of plastida is strongly influenced by excitatory light.
Plasticide is distinguished into three kinds, namely:
Leukoplas is a white or colorless plastida found in root cells, tubers, and seeds. Based on the type of material stored, leukoplas are distinguished into amiloplas (storing amamlum), eaioplas (storing oil), and proteoplas (storing proteins).
Chromoplas is a plasticide that contains pigments other than chlorophyll (green), e.g. fikoeritrin (red), fikosianin (blue), fikosantin (brown), carotene (yellow), and others. Chromoplas is found in flower cells and ripe fruits.
Chloroplasty is a plasticide shaped like a lens and contains green pigments (chlorophyll). Chloroplasts are found in cells that perform photosynthesis, such as leaf cells and green algae. Chloroplasts also have two parts, namely grana and stroma. Grana is a pile of a number of tilakoids. Tilakoid is a flat-shaped pouch. As for, stroma is a liquid that is outside the tilakoid. In stroma is contained a wide variety of substances, such as enzymes, organic acids, and carbohydrates resulting from photosynthesis in the form of flour.